Antibody response of sheep to simultaneous vaccination of foot-and-mouth disease, peste des petits ruminants, sheep pox and goat pox, and bluetongue vaccines.

There are many infectious animal diseases in T urkey and generally, vaccination is the primarly control strategy to combat them. However, it is difficult to apply all vaccines in a definite period in the field due to limitations of the labor and finance. Rapid vaccination and effective use of labor can be possible with the help of simultaneous vaccine administrations. The study aims to show the effects of simultaneous foot-and-mouth disease (FMD), peste des petits ruminants (PPR), sheep pox and goat pox (SGP), and bluetongue (BT) vaccine administration on the antibody response of sheep. For this aim, 30 sheep were divided into one experiment and 5 control groups. Blood samples were collected in each group at 0, 30 and 60 days post-vaccination (DPV). Immune response was measured with virus neutralization test (VNT) and, liquid phase blocking ELISA (LPBE) for FMDV; VNT for BTV and PPR. A live virus challenge study was performed to determine the immune response of SGP vaccine. As a result, antibody titers for each vaccine agent decreased on 60 DPV with the simultaneous vaccination except FMD. The difference between means of antibody titer decrease with single and simultaneous vaccinations is significant especially for BTV and PPR vaccines at 60DPV (p<0.05). Briefly, this decreasing immune response of three live vaccines can be explained with the development of the interference, administration of these vaccines from the same injection site, the effect of cytokines, especially IL-10 effect of SGP vaccine. It was concluded that four vaccines can not be used simultaneously in sheep.

Evaluation of antibody response of sheep to foot-and-mouth disease vaccine prepared by using different MontanideTM oil adjuvants.

Despite the widespread use of the conventional inactivated foot-and-mouth disease (FMD) vaccine, its immunogenicity is poor and the duration of its protection is short. In this study, humoral response to commercial ready-to-use MontanideTM ISA 201 VG and MontanideTM ISA 61 VG oil adjuvants and a common adjuvant MontanideTM ISA 206 VG developed by Seppic Inc., were evaluated for FMD antigens in sheep and double oil emulsion (w/o/w) formulations of MontanideTM ISA 201 and 206 and single oil emulsion (w/o) of MontanideTM ISA 61 have been prepared by using current FMDV antigens (O/TUR/07, A/ASIA/G-VII, A/TUR/16 and ASIA/ TUR/15). The animals (n=48) were vaccinated subcutaneously with formulations and five sheep were maintained as an unvaccinated control group. Blood samples were taken at day 0, 7, 14, 21, 28, 60, 90, 120 and 150. Virus neutralization and liquid phase blocking ELISA tests were used to compare antibody response to vaccines prepared by using different MontanideTM mineral oils. The results showed that vaccines prepared by using MontanideTM ISA 61 and 201 gave better antibody response to FMD antigens than MontanideTM ISA 206 formulation, although results were not statistically significant for certain days of sampling. Moreover, the overall type O antibody response of MontanideTM ISA 201 was found to be superior to MontanideTM ISA 61.

Effect of FMD vaccination schedule of dams on the level and duration of maternally derived antibodies.

Vaccination against Foot and Mouth Disease (FMD) in pregnant cows is crucial to produce greater immunity in new born calves, especially in late gestation, as this directly affects neonatal immunity. Therefore, we aimed to investigate how late gestation FMD vaccination of pregnant cows affects the maternally derived antibodies in their offspring. Pregnant cows were vaccinated with and without booster vaccination during the 3rd months (early gestation vaccination, EGV) or the 6.5th months (late gestation vaccination, LGV). Their offspring were investigated for passive immunity transfer, maternal antibody duration, and the first vaccination age of calves (when the maternal antibody has waned sufficiently to allow the first vaccination). Antibody titers were analyzed by a virus neutralization test (VNT). A digital Brix refractometer (% Brix) was used to estimate passive antibody transfer efficiency measuring total protein (TP) content of calf blood sera and also colostrum IgG content. Two linear mixed effects models were fitted: one for the antibody titer values of the dams, and the other for the antibody titer values of calves before the vaccination. A marginal fixed effects model was also fitted to explore the effects of the dam titers on the antibody titers of the calves after their vaccinations. As a result, the average neutralizing antibody titers did not differ between the EGV and LGV groups nor were any differences detected between dams that received a booster and those that were not boosted. However, the LGV calves' mean maternally derived antibody titers were significantly higher (p-values = 0.0001 for both groups) and the duration was longer than that of the EGV calves (120 days in LGV, 60 days in EGV, p < 0.05). Since no statistical difference was found between the titers of either group of dams at the beginning of the experiment and parturition, it does not appear that the higher VN titers in LGV calves compared to titers in EGV are directly related to the circulating antibody levels in the dams. Furthermore, the TP value (% Brix) of calf blood sera was higher than>8.4% in both calf groups (9.3 ±â€¯0.33 in LGV and 8.6 ±â€¯0.40 in EGV, p > 0.05) indicating that passive immunity transfer had occurred for both groups. In addition, we found that the % Brix mean colostrum IgG content of the LGV (25.8 ±â€¯1.30) was higher than the EGV (21.8 ±â€¯0.58) dams (p < 0.01) and a significant positive correlation found between the colostrum density of LGV dams and TP (% Brix) value of their offspring (r = 0.73, p < 0.01). Our results show that vaccination during the late gestation period increased the colostrum IgG content of dams of LGV in addition to the maternally derived antibody duration and potentially provided greater protection of the offspring.

Characterisation of foot-and-mouth disease virus strains circulating in Turkey during 1996-2004.

Two genotypes of foot-and-mouth disease virus serotype A were identified as the cause of disease outbreaks in Turkey during 1996-2004, while serotype O strains, identified during the same period, seem to represent an evolutionary continuum, and Asia1 strains were only rarely identified. The data presented are concordant with the conclusion that serotype A strains are repeatedly introduced to Turkey from the east and circulate only transiently in farming communities, while type O strains persist and re-emerge from endemic areas of Turkey. The co-circulation of strains belonging to two A genotypes for 6 years, as observed in the present study, is a remarkable difference compared to previous decades in which only one A genotype was transiently circulating, successively being replaced by others. This co-circulation was observed in spite of enforcement countrywide of biannual vaccination of more than 50% of the cattle during the same period. Mean r(1) values of 0.70 +/- 0.19 and 0.39 +/- 0.04 found for A96 and A99 isolates, respectively, compared to the A96 vaccine component reveal antigenic differences but also imply that the vaccine in use in Turkey should provide protection against both genotypes. It is suggested that further studies to reveal the nature of the difference in epidemiological dynamics of type A and type O strains might lead to an understanding of the measures required to control foot-and-mouth disease in islands of persistent circulation.